STAINING FLUIDS. 27 



Solution of alum-carmine. Grenadier recommends this 

 fluid : Take a one to five per cent, solution of ordinary alum, 

 or ammonia alum ; boil with one-half to one per cent, powdered 

 carmine for twenty minutes. Filter, and add a little carbolic 

 acid to preserve. 



Naphthaline yellow for bone. In sections of the femur 

 from a foetal pig, three and a half inches in length, the follow- 

 ing method was found to yield very excellent results : 



After immersion for three days in Miiller's fluid, sections 

 were made, and, after washing in water, immediately dipped in 

 an alcoholic solution of naphthaline yellow (gr. iv. J j.) ; after 

 eight to ten minutes the sections were removed, and dipped in 

 a watery solution of acetic acid of three per cent. ; then they 

 were immersed for about ten minutes in the ordinary solution 

 of ammonia-carmine, rendered neutral by exposure to the 

 air. 



The sections were again dipped in the acetic acid solution 

 in order to set the color, and then placed in alcohol of eighty 

 per cent., and subsequently in absolute alcohol. 



The specimens thus stained showed a matrix of deep trans- 

 parent chrome yellow. The young bone-corpuscles and osteo- 

 blasts, on the other hand, together with the fibrous tissue, 

 assumed a brilliant rose color, thus affording an excellent con- 

 trast between forming and formed bone. 



Staining with methyl-green and induline. Calberla has 

 introduced two new substances into use, viz., methyl-green and 

 induline. The one stains the nuclei of the cells of the sub- 

 cutaneous tissue, the nuclei of vessels and nerve-sheaths rose 

 color, while the cells of the corium and their nuclei are a 

 violet red ; the other colors the cells of the Malpighian layer 

 a greenish blue. Combinations of methyl green and eosine are 

 also recommended. Eosirie (one part) and methyl green (sixty 

 parts) are to be dissolved in a thirty per cent, solution of warm 

 alcohol. The epithelial nuclei take a violet blue, the nuclei 

 of connective tissue a greenish blue, and the cell-body a red 

 color. Singular differentiations are made ; thus, while the 

 striated muscle is red, the nuclei are green. On the other 

 hand, smooth muscular tissue is green, and the intercellular 

 substance red. In the salivary glands the cells of the excretory 

 ducts are blue, while the so-called secretory cells are red. In- 

 duline dissolves in warm water and in dilute alcohol. Take a 



